A method and apparatus for sharing digital content and a system for sharing digital content are provided. A multimedia device, such as an Internet Protocol Television (IPTV), as the apparatus for sharing digital content, includes a decoder for decoding digital content data; a Digital Signal Processor (DSP) for encoding the digital content data decoded by the decoder to have a data format which a remote device supports; and a network interface for transmitting the digital content data re-encoded by the DSP to the remote device. In the present invention, once a user subscribes for a content providing service for the IPTV, the user is able to watch digital content of the IPTV in a remote place by using the mobile phone, or the like without separately subscribing for a service for the mobile phone.